The present invention relates to a means for preventing the noise generated inside of a vehicular charging generator from being transmitted to the outside.
In the prior art, the noise prevention means for a magneto of the above-identified type has been constituted by a single capacitor in an output circuit. More effective countermeasures are demanded in accordance with the increasing use of wireless devices and digital appliances.
FIG. 1 is a view of the internal construction of a rear bracket of one example of a vehicular charging generator according to the prior art. FIG. 1(A) is a top plan view; and FIG. 1(B) is a partially sectional view taken along line a-b-c-d of the top plan view of FIG. 1(A).
In these Figures, reference numerals 1, 2 and 3 indicate a rear bracket, a fastening seat of the former, and an output terminal seat of the rear bracket 1, respectively. Numeral 4 indicates a rectifier which is mounted in the rear bracket 1. A noise absorbing capacitor 5 is fastened together with the rectifier. A connecting plate 6 introduces the output of the rectifier to an output terminal 7. An output terminal bolt 8 is fixed in the output terminal seat 3 through insulating bases 9 and 10 by means of a hexagonal nut 11, and a brush holder 12 is fastened together with the output terminal bolt. A hexagonal nut 13 fastens the output terminal 7 on to the output terminal bolt 8 through a spring washer 14. Numeral 15 indicates a harness which is connected with the output terminal 7.
In the vehicular charging generator constructed as described above, the noise generated inside thereof is transmitted from the rectifier 4 through the connecting plate 6 and the output terminal 7 to the outside. However, this is absorbed by the capacitor 5 because the floating inductance belonging to the harness 15 connected with the outside, as illustrated in FIG. 2, functions as a choke element although it is at a low level. Here, FIG. 2 is a connection diagram showing the output portion of the vehicular generator. Reference numerals 2, 5 and 7 appearing in FIG. 2 indicate identical or corresponding portions as those in FIG. 1. In FIG. 2, numeral 18 indicates the floating inductance of the harness.
Since the floating inductance 18 has a low value, its noise absorbing effect is not necessarily sufficient and thus the effect is insufficient to meet the recent demand for noise reduction even if it is replaced by a capacitor having excellent characteristics.